scholarly journals Physics Essay: Particle Nature of Light and the Speed of Light

2015 ◽  
Vol 7 (6) ◽  
pp. 49
Author(s):  
Zifeng Li
Keyword(s):  
Light Source ◽  
Wave Reflection ◽  
Group Behavior ◽  
Light Particle ◽  
Speed Of Light ◽  
The Earth ◽  
Particle Nature

<p class="1Body">What is the nature of light? Particle or wave? How fast is the speed of light? These are all basic questions of physics. From points of philosophy and observation, it is demonstrated that the nature of light is a kind of particle, and many photons’ group behavior is of characteristics similar to the wave. Reflection, diffusion, refraction and transmission of light are all phenomenon of matter’s attraction, absorption and re-emission of photons. Until now, there is no accurate means of measuring the speed of light. For the speed of starlight relative to the earth, the closer to the earth, the closer to the speed of light emitted by a light source on the earth relative to the earth. Physics field is composed of space and tiny particles.</p>

scholarly journals Methods to Test the “Dimming Effect” Produced by a Decrease in the Number of Photons Received from Receding Light Sources

2021 ◽  
Author(s):  
Mark Zilberman ◽  
Keyword(s):  
Light Source ◽  
Opposite Direction ◽  
Cosmological Models ◽  
Light Sources ◽  
The Sun ◽  
Relative Speed ◽  
Speed Of Light ◽  
Relativistic Systems ◽  
The Earth

The hypothetical “Dimming effect” describes the change of the number of photons arriving from a receding light source per unit of time. In non-relativistic systems,the "Dimming effect" occurs due to the fact that as light sources move away, the distance between the emitter and the receiver constantly increases, and the photons always take longer to reach the receiver. This reduces the number of photons received per time unit compared to the number of emitted photons per time unit. Negligible for speeds incomparable with the speed of light c, the "Dimming effect" can be very significant for speeds above 0.1c. “Dimming effect” can possibly be tested in a physics labor-atory using a moving light source (or mirror) and photon counters located in the travel direction and in opposite direction. It can possibly also be tested utilizing the orbital movement of the Earth around the Sun. If confirmed, “Dimming effect” would allow astronomers to adjust values of the "Standard Candles", which are critical in cosmological models. Absence of “Dimming effect” will mean that the number of photons arriving per time unit does not depend on the relative speed of light source and observer,which is not so apparent

INFLUENCE OF MAGNETIC CHARGE ON THE SAGNAC EFFECT IN THE BARDEEN SPACETIME

2021 ◽  
Vol 0 (1) ◽  
pp. 92-96
Author(s):  
R.KH. KARIMOV ◽  
◽  
K.K. NANDI ◽  
Keyword(s):  
Black Hole ◽  
Light Source ◽  
Magnetic Charge ◽  
Sagnac Effect ◽  
Modified Theories Of Gravity ◽  
Circular Orbits ◽  
The Earth ◽  
Astrophysical Objects ◽  
Interesting Task ◽  
Theories Of Gravity

This paper investigates one of the most interesting effects associated with the rotation of astrophysical objects (the Sagnac effect). The effect was first confirmed in laboratory experiments by Georges Sagnac with a rotating ring interferometer in 1913. Later, the effect was also confirmed within the framework of the Earth in the "Around-the-World" experiment conducted by J. Hafele and R. Kitting, in which they twice circled the Earth with an atomic cesium clock on board and compared the "flying" clock with those remaining static on the Earth. As a result, a non-zero difference in the clock rate was found as a confirmation of the Sagnac effect. Subsequently, more precise satellite experiments have been carried out to measure the Sagnac effect within the Earth. The effect was also considered in general relativity and modified theories of gravity, where many works were carried out to study the influence of such parameters as angular momentum, cosmological constant, Ricci scalar, etc. on the Sagnac effect. An interesting task is to study the influence of a magnetic charge on the effect, since the solution with rotation described by a black hole with mass M and magnetic charge g is the Bardeen nonsingular black hole. The work will calculate the Sagnac effect in the space-time of the rotating Bardeen black hole for both geodesic and non-geodesic circular orbits of the light source / receiver (assuming that the light source and receiver are defined at the same point). Two types of circular orbits describe the opposing influence on the Sagnac effect: the Sagnac delay increases with an increase in the magnetic charge in the case of non-geodesic circular orbits and decreases in the case of geodesic circular orbits. However, the farther is the orbit of the light source / receiver, the less the magnetic charge affects the Sagnac delay. It is also assumed that the gravity of the Earth and the Sun near the surface is well described by the Bardeen metric.

scholarly journals Methods to Test the “Dimming Effect” Produced by a Decrease in the Number of Photons Received from Receding Light Sources

2020 ◽  
Author(s):  
Mark Zilberman
Keyword(s):  
Light Source ◽  
Opposite Direction ◽  
Ecliptic Plane ◽  
Light Sources ◽  
The Sun ◽  
Decimal Point ◽  
Relativistic Systems ◽  
The Earth ◽  
New Models ◽  
Direction Opposite

The hypothetical “Dimming Effect” describes the change of the number of photons arriving from a moving light source per unit of time. In non-relativistic systems, the “Dimming effect” may occur due to the growing distance of light sources moving away from the receiver. This means that due to the growing distance, the photons continuously require more time to reach the receiver, which reduces the number of received photons per time unit compared to the number of emitted photons. Understandably, the proposed “Dimming effect” must be tested (confirmed or rejected) through observations. a. This article provides the formula for the calculation of “Dimming effect” values using the redshift parameter Z widely used in astronomy. b. The “Dimming effect” can possibly be detected utilizing the orbital movement of the Earth around the Sun. In accordance to the “Dimming effect”, observers on Earth will view 1.0001 more photons per time unit emitted by stars located near the ecliptic plane in the direction of the Earth orbiting the Sun. And, in contrast, observers will view only 0.9999 photons per time unit emitted by stars located near the ecliptic plane in the direction opposite to the Earth orbiting the Sun. Calculating precise measurements of the same stars within a 6-month period can possibly detect this difference. These changes in brightness are not only for specific stars, as the change in brightness takes place for all stars near the ecliptic in the direction of the Earth’s orbit around the Sun and in the opposite direction. c. The “Dimming effect” can possibly be detected in a physics laboratory using a moving light source (or mirror) and photon counters located in the direction of travel and in the opposite direction. d. In theory, Dilation of time can also be used for testing the existence of the “Dimming effect.” However, in experiments on Earth this effect appears in only the 14th digit after the decimal point and testing does not appear to be feasible. e. Why is it important to test the “Dimming effect?” If confirmed, it would allow astronomers to adjust values of "Standard Candles" used in astronomy. Since “Standard Candles” are critical in various cosmological models, the “Dimming effect” can correct models and/or reveal and support new models. If it is proved that the “Dimming effect” does not exist, it will mean that the number of photons arriving per unit of time does not depend on the speed of the light source and observer, which is not so apparent.

scholarly journals SUBLUMINAL OPERA NEUTRINOS

2012 ◽  
Vol 27 (07) ◽  
pp. 1250033 ◽  
Author(s):  
ICHIRO ODA
Keyword(s):  
Special Relativity ◽  
Recent Work ◽  
Causal Structure ◽  
Pion Decay ◽  
Speed Of Light ◽  
The Earth

The OPERA Collaboration has announced to have observed superluminal neutrinos with a mean energy 17.5 GeV, but afterward the superluminal interpretation of the OPERA results has been refuted theoretically by Cherenkov-like radiation and pion decay. In a recent work, we have proposed a kinematical resolution to this problem. A key idea in our resolution is that the OPERA neutrinos are not superluminal but subluminal since they travel faster than the observed speed of light in vacuum on the earth while they do slower than the true speed of light in vacuum determining the causal structure of events. In this paper, we dwell upon our ideas and present some concrete models, which realize our ideas, based on spin 0, 1 and 2 bosonic fields. We also discuss that the principle of invariant speed of light in special relativity can be replaced with the principle of a universal limiting speed.

James Bradley, Sailing on the Thames

Lightspeed ◽  
2019 ◽  
pp. 49-57
Author(s):  
John C. H. Spence
Keyword(s):  
Eighteenth Century ◽  
Experimental Evidence ◽  
The Sun ◽  
Theory Of Relativity ◽  
Speed Of Light ◽  
Astronomical Observations ◽  
The Earth ◽  
Independent Estimate ◽  
The Universe ◽  
At Home

The story of the astronomical observations of James Bradley in the eighteenth century, whose measurements of the small movements of a star throughout the year provided an independent estimate of the speed of the Earth around the Sun relative to the speed of light. His work provided the first experimental evidence in support of Copernicus’s theory that the earth is in motion, and against the idea that it is stationary at the center of the universe. His simple telescope at home, his brilliant idea and perseverance, and his life’s work and influence. The importance of his result for the development of Einstein’s theory of relativity and for theories of the Aether in the following centuries.

Ole Roemer, Who Started It All

Lightspeed ◽  
2019 ◽  
pp. 18-26
Author(s):  
John C. H. Spence
Keyword(s):  
Life Story ◽  
The Sun ◽  
Speed Of Light ◽  
The Earth ◽  
At Home

The story of the first measurement of the speed of light by Ole Roemer in 1676. Galileo had discovered the moons of Jupiter with his new telescope, and proposed using observations of their eclipse every forty-two hours as a universal clock for our planet, since they could be seen from practically anywhere. This would keep track of the time at home, and so give a traveller his or her local longitude. (The King of Spain had offered a prize for longitude determination to avoid disasterous shipwrecks.) Roemer noticed that the eclipses were sometimes a little late, which he concluded was due to the time it took light to get from Saturn to Earth and the movement of the Earth between eclipses. His estimate of the time for light to travel from the Sun to Earth was quite accurate. Roemer’s remarkable life story and many other achievements are told.

scholarly journals Radar determination of the Astronomical Unit

1965 ◽  
Vol 21 ◽  
pp. 177-215
Author(s):  
Irwin Shapiro
Keyword(s):  
Time Delay ◽  
Astronomical Unit ◽  
Speed Of Light ◽  
Comprehensive Review ◽  
A Value ◽  
The Earth ◽  
Lincoln Laboratory ◽  
Data Yield ◽  
Shift Data

A comprehensive review is given of the Earth-Venus measurements made with the Lincoln Laboratory Millstone radar in 1959 and 1961. The time-delay and Doppler shift data yield a value for the Astronomical Unit of 499.0052 ± 0.001 light-sec. Using 299 792.5 km/s for the speed of light leads to an AU of 149 598 000 ± 300 km. With the radius of Earth taken as 6 378.15 km, the solar parallax then becomes 8″.79416 ± 0″.00002. This value is consistent with measurements made at various other laboratories to about one part in 105.

Achieving Human Presence in Space Exploration

2013 ◽  
Vol 22 (4) ◽  
pp. 345-349 ◽  
Author(s):  
Dan Lester
Keyword(s):  
Space Exploration ◽  
Human Cognition ◽  
Speed Of Light ◽  
Human Spaceflight ◽  
Human Presence ◽  
The Earth ◽  
New Perspective ◽  
The Way

One of the primary goals of human spaceflight has been putting human cognition on other worlds. This is at the heart of the premise of what we call space exploration. But Earth-controlled telerobotic facilities can now bring human senses to other worlds and, in that respect, the historical premise of exploration, of boots on the ground, no longer clearly applies. We have ways of achieving remote presence that we never used to have. But the distances over which this must be achieved, by humans based on the Earth, is such that the speed of light seriously handicaps their awareness and cognition. The highest quality telepresence can be achieved not only by having people on site, but also by having people close, and it is that requirement that truly mandates human spaceflight. In terms of cost, safety, and survival, getting people close is easier than getting people all the way there. It is suggested here that to the extent that space exploration is best accomplished by achieving a sense of real human off-Earth presence, that presence can be best achieved by optimally combining human spaceflight to mitigate latency, with telerobotics, to keep those humans secure. This is culturally a new perspective on exploration.

scholarly journals Mach–Zehnder fiber interferometer test of the anisotropy of the speed of light

2009 ◽  
Vol 87 (9) ◽  
pp. 999-1008 ◽  
Author(s):  
Victor de Haan
Keyword(s):  
Optical Fiber ◽  
Phase Difference ◽  
Main Direction ◽  
The Other ◽  
Earth Surface ◽  
Temperature Stabilization ◽  
Speed Of Light ◽  
The Earth ◽  
Better Than ◽  
Phase Differences

Two optical fiber Mach–Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer consisted of a length of 12 m optical fiber in each arm, with the main direction of the arms perpendicular to each other while the other consisted of a length of 2 m optical fiber in each arm, where the main direction of the arms are parallel, and served as a control. In each arm, 1 m of fiber was wound around a ring made of piezo material, enabling the control of the length of the arms by means of an applied voltage. The influence of the temperature on the optical phase difference between the interferometer arms was measured. The temperature change induced a variation of the interaction region of the optical fiber couplers. Further, the influence of rotation of the interferometers at the Earth surface on the observed phase differences was determined. For one interferometer (with the long and perpendicular arms), it was found that the phase difference depends on the azimuth of the interferometer. For the other one (with the short and parallel arms), no relevant dependence on the azimuth has been measured.

scholarly journals Navigation, world mapping and astrometry with Galileo's moons

2010 ◽  
Vol 6 (S269) ◽  
pp. 42-48 ◽  
Author(s):  
Kaare Aksnes
Keyword(s):  
Light Curves ◽  
Speed Of Light ◽  
Finite Speed ◽  
The Earth

AbstractGalileo realized that the four moons he discovered, besides supporting the heliocentric system, could also serve as a clock in the sky for longitude determination. Navigation at sea by this method did not prove practical but G. Cassini used it to improve land mapping. O. Rømer discovered that the interval between eclipses of the moons by Jupiter increased or decreased according to whether the Earth moved away from or toward Jupiter. He attributed this to the finite speed of light which he in 1676 determined with an error of about 25%. Timings of the eclipses by Jupiter have served to compute accurate orbits of the moons, notably by means of R. A. Sampson's theory of 1921. Beginning in 1973, light curves of mutual eclipses and occultations between pairs of moons have been made regularly at six years intervals. From these observations very accurate radii and positions of the moons have been obtained.

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